Science. 1984 Mar 16;223(4641):1180-3. doi: 10.1126/science.223.4641.1180.
Iridium concentrations are anomalously high at the palynological Cretaceous-Tertiary boundary in fluvial sedimentary rocks of the lower part of the Raton Formation at several localities in the Raton Basin of New Mexico and Colorado. The iridium anomaly is associated with a thin bed of kaolinitic claystone in a discontinuous carbonaceous shale and coal sequence.
铱浓度在新墨西哥州和科罗拉多州拉顿盆地几个地方的拉顿组下部河流沉积岩的孢粉化石中出现异常高值。该铱异常与不连续的碳质页岩和煤序列中的一层薄高岭石粘土岩有关。
